What is the only reliable way to determine if a home has radon?

Testing is the only reliable way to determine if a home has radon. Radon is an odorless, colorless gas that can seep into homes from the ground, and it poses health risks when accumulated in high levels indoors. Visual inspection cannot detect radon because it is invisible and cannot be identified through sight alone. Similarly, asking a neighbor about radon levels in their home would not provide accurate information about the specific levels in a different house, as radon can vary significantly even between neighboring properties. While assessing the age of the building might help to understand potential radon risks based on building materials or construction methods used, it does not definitively indicate whether radon is present. Testing directly measures the concentration of radon in the air, providing homeowners with the necessary information to assess their exposure and take potential mitigating actions if needed.